Typically, during the opening process of the roof opening a drive slide is displaced in the vehicle longitudinal direction. In this case, a rear edge of the cover facing the rear of a vehicle is initially raised so that the cover is obliquely positioned. This position is also denoted as the ventilation position. In the usual manner, at the same time a front edge of the cover is lowered since the cover rotates about a front bearing point of a front deployment lever. In this case, during the movement of the cover from the closed position into the ventilation position relative to a vehicle longitudinal direction the deployment lever is stationary. The lowering of the cover front edge downwardly may be, for example, up to 6 mm or more.